Effect of a cholecystokinin (CCK) antagonist (CR 1505) on gene expressions of CCK and secretin in rat intestine.

The effects of intragastric administration of cholecystokinin (CCK) antagonist (CR 1505; 60-300 mg/kg/day) to rats for 3 days on the gene expressions of CCK and secretin, the plasma CCK immunoreactivity, and the CCK content in the intestinal mucosa were examined. CR 1505 increased the level of CCK mRNA in the intestine dose dependently to up to 1.6 times the level in control rats but did not affect the level of secretin mRNA. It also significantly increased the plasma CCK immunoreactivity and the amount of CCK extracted from intestine with acid dose dependently. CR 1505 tended to decrease the trypsin activity in the intestine. These results suggest that ingested CR 1505 increased the CCK mRNA level in the intestine.